Self-carrying cable



NOV 5, 1940- E.' c. BYLANDER 2,229,393

SELF-CARRYING CABLE Filed, Feb. 4, 1938 Patented Nov. 5, 1940 PATENT OFFICE SELF-CARRYING CABLE Erland Cornelius Bylander, Sundbyherg, Sweden, assignmto Telefonaktiebolaget L. M. Ericsson,

Stockholm, Sweden Application February 4, 1938, Serial No. 188,795

1 Claim.

The present invention relates to a leadsheathed electric aerial cable arranged for being stretched in free spans Without the use of a suspending wire. A self-carrying cable of this kind 5 is previously known inV which a carrying Wire made of steel is impressed within the lead sheathing. The invention has for its object to improve cables of said kind and consists essentially therein that the carrying wire is in the form of a l plane ilexible steel tape which is provided with at least one friction surface cooperating, in consequence of the lead sheath being pressed around the cable core, with the insulated conducting wires located in a plane.

According to an embodiment of the invention, also the other side of the steel tape is designed to form a friction surface which may cooperate either with the lead sheath or with conducting wires arranged in a plane.

Through the invention that advantage is gained, as compared with known designs, that a high friction is obtained between the carrying member and the conducting wires as well as the lead sheath so as to avoid mutual displacement 25 between these parts of the cable. The cable is stretched by means of suitable tightening or clasping members which compress the cable at the ilxing points and further increase the friction between the different parts of the cable at 30 said points. Thus, oating or sliding of the lead sheath at the fixing points is not to be feared in case of a cable designed according to the present invention.

are then placed onto a flexible steel tape 4 which 10 has been endowed with two friction surfaces 5 and 6 by that the steel tape has been closely lwound with thin yarn 8. Another way of providing friction surfaces is to let the steel tape pass between toothed rollers. The steel tape and the wires are pressed together by means of a lead sheath l pressed around the two parts. Prior to covering the cable core with the lead sheath, the cotton tape and the other insulation are soaked with a suitable impregnating agent.

I claim: v

A self-carrying cable of great tensile strength, comprising a planel flexible steel tape provided with two friction surfaces uniformly spread over substantially the Whole length of the tape, at least one pair of insulated conducting wires arranged at least closely to the one of the said friction surfaces of said tape and parallel to the same and a lead sheath closely pressed around said tape and said insulated conductors.

ERLAND CORNELIUS BYLANDER. 

